Re: [patch]: fixing of pmtimer overflow that make Cx states time incorrect

Andrew Morton
2009-02-09T19:58:59Z

On Mon, 02 Feb 2009 09:46:57 +0800
"alex.shi" <alex.shi@intel.com> wrote:

> Yagui want to give a clear explanation to be used for commitment. So I resend
> this again.
>
> On most boxes the ACPI PM timer is 24-bit counter that runs on 3.579545MHz
> clock. In such case the max C-state sleep time should be less than 4687ms when
> it is used to record C2/C3 duration time.
> But on some boxes the max C-state sleep time is more than 4687ms. In such
> case the overflow happens and the C-state duration time can't be counted
> accurately.
>
> Use clocksource to get the C-state time instead of ACPI PM timer. and use
> div64_u64 to convert US_TO_PM_TIME_TICKS in i386 mode.

It seems that this bugfix was not applied, a cleanup patch was merged
instead and this patch is now wrecked.

I'll need to drop it, sorry.